The invention relates to a transmission for a trimmer/mower, a trimmer/mower having a transmission and in particular to a transmission for a trimmer/mower that is readily mountable to the trimmer/mower.
Conventional trimmer/mowers have a trimmer/mower head that is driven by a vertically extending shaft driven in rotation by an electric motor or internal combustion engine. For cutting grasses and other thin stemmed vegetation, a line trimmer head having monofilament line extending from the periphery of the head is typically used. For cutting larger diameter stalks, including brush and small trees, disc-shaped blade attachments are known to be used. By using such attachments, the trimmer/mower can be used for more than one purpose. However, the vertical orientation of the driven shaft of the trimmer/mower limits the range of attachments that can be used in place of, or in addition to, the rotating trimmer head.
For attachments that perform work in a vertical plane, a horizontally extending driven shaft is required. However, horizontally extending drive shafts are not suitable for use with a trimmer head that cuts vegetation generally parallel to the ground surface, which is the trimmer/mower""s primary function. Accordingly, trimmer/mowers of the prior art have limited versatility and are not able to support the use of attachments that perform work in a vertical plane (rotating about a horizontal axis) with respect to the ground.
It is an object of the present invention to use a transmission with a trimmer/mower that drivingly connects to a drive shaft of a trimmer mower and that has an output drive shaft driven for rotation generally horizontally with respect to the ground surface.
It is a further object of the invention to readily mount and dismount such a transmission from a trimmer/mower, preferably without the need for tools using a simple, quick mounting procedure.
It is yet a further object of the invention to be able to readily mount and dismount such a transmission to a trimmer/mower that is provided with or retrofit with a bearing housing to which the transmission is to be mounted.
According to a preferred embodiment of the invention, a suitable transmission is a worm-gear drive transmission that mounts on the bearing housing of a trimmer/mower and drivingly engages the vertically oriented shaft that is driven by the trimmer/mower. Further, preferably the worm gear drive has an output shaft that is horizontally oriented and rotates at a reduced speed and higher torque with respect to the vertically oriented shaft.